Permanent press fabric resin and processes therefore

ABSTRACT

2,7-dioxo-4,5-dimethyl-decahydropyrimido-(4,5-d)-pyrimidine is reacted with glyoxal and the resulting adduct methylolated with formaldehyde to produce the corresponding methylolated derivative which exhibits very desirable properties as a permanent press resin for fabrics.

United States Patent [191 Powanda et a1.

[ Aug. 21, 1973 1 PERMANENT PRESS FABRIC RESIN AND PROCESSES THEREFORE [75] Inventors: Thomas M. Powanda, Middlesex;

Lawrence B. Holzman, West Orange; James E. Tracy, Bernardsville, all of [73] Assignee: Celanese Corporation, New York,

[22] Filed: Apr. 20, 1971 21 Appl. No.: 135,778

[52] US. Cl 8/115.7, 8/115.6, 8/1 16.3,

38/144, 260/2564 F, 260/675 [51] Int. Cl. D06m 15/54, C07d 51/42 [58] Field of Search 8/1 16.3; 8/1 15.7

Ziguenner et al., Monatshefte fuer Chemie, 92, 42-51 (1961) Gagliardi, D. D., in Advances in Textile Processing, Vol. 1, J. E. Lynn and J. J. Press, eds., Interscience, New York, 1961, pp. 170 and 190 Primary Examiner-George F. Lesmes Assistant Examiner-J. Cannon Attorney-Thomas J. Morgan, Marvin A. Turken and Charles E. Miller [5 7 ABSTRACT 2,7-dioxo-4,S-dimethyl-decahydropyrimido-[4,5-d] pyrimidine is reacted with glyoxal and the resulting adduct methylolated with formaldehyde to produce the corresponding methylolated derivative which exhibits very desirable properties as a permanent press resin for fabrics.

7 Claims, No Drawings PERMANENT PRESS FABRHC RESIN AND PROCESSES THEREFORE BACKGROUND OF THE INVENTION like apparel. It is anticipated, for instance, that use of permanent press resins in household white goods, e.g., sheets, pillowcases and tablecloths, will account for a substantial amount of the increased demand in the future. To meet this demand the resins must be able to impart permanent press properties without degrading the fiber from which the fabric is made. Typically, the fabric is cellulosic in nature, for example, cotton, cotton-polyester blends, regenerated cellulosic materials, such as rayon, and the like. Degradation can occur, for example, when the resin finish is applied and cured; it may also occur as a result of repeated washings of the treated fabric using the various popular bleaches and detergents.

The concept of permanent press is twofold: crease resistance and crease retention. Crease resistance is synonymous with wrinkle resistance and wrinkle recovery, viz., the ability of a treated fabric to resist wrinkling and to retain smoothness of shape and hand upon repeated wear and laundering. Crease retention" is synonymous with durable press, viz., the ability of a treated fabric to drip-dry without loss of crease and to be worn without ironing.

Clearly, the achievement of all of these desirable properties, and others such as resistance to soil redeposition, and the like, requires chemicals which are quite special.

Therefore, it is an object of the present invention to provide a novel composition of matter which, when ap plied to a fabric particularly a cellulosic fabric, imparts a colorless, permanent press finish thereto.

Another object is to provide a process for producing a novel composition of matter which, when applied to a fabric, particularly a cellulosic fabric, imparts a colorless, permanent press finish thereto.

Another object is to provide a permanent press fabric finish.

Yet another object is to provide a process for applying to a fabric, and particularly to a cellulosic fabric a permanent press finish.

These and other objects of the present invention, as well as a fuller understanding of the advantages thereof, can be had by reference to the following detailed description and claims.

DETAILED DESCRIPTION OF THE INVENTION The above objects are achieved according to the present invention by the discovery of novel chemical compositions from which useful resins can be readily prepared, the latter exhibiting, as will be seen hereinafter, permanent press characteristics of the type intensely sought after by the textile industry and hereinbefore briefly described. The novel compounds ofthe present invention are prepared from 2,7-dioxo-4,5- dimethyl-decahydropyrimido-[4,5-d]-pyrimidine, (A), which has the following formula:

by reacting (A) with glyoxal to form the dihydroxyethyl-substituted adduct material, (B), which is repre sented by the following formulae:

N 01f CHI IEIN which in turn is treated with formaldehyde or source thereof to produce the corresponding methylolated material, (C), which is represented by the following formula OH (E) N of on; -N

iii 0 wherein n is an integer from 1 to 2, inclusive. Material (C) is useful for treating fabrics, pursuant to the present invention, to impart significant and desirable permanent press characteristics to the fabrics so treated.

The compound 2,'i-dioxo-4,5-dimethyldecahydropyrimido-[4,5-d]-pyrimidine, is reported in 92 Monatshefte fuerChemie 31 (1 961) as acrystalline solid melting at 277C. This material can be prepared according to the aforementionedreferenceby the acidcatalysed reaction between acetaldehyde and urea in aqueous menstruum. The ratio of "the concentration of acetaldehyde to that of urea in the reaction system is at least about 1.5, and preferably between. about 1.8 and about 2.2. The reaction is desirably conducted at atmospheric pressure and at an elevated temperature, preferably at a temperature of between about 50C. and about C with the atmospheric reflux temperature of the reaction system being especially preferred.

It is desirable that the 2,7-dioxo-4,5-dimethyldecahydropyrimido-[4,5-d]-pyrim1idine be employed in a high state of purity, i.e., in crystalline form. ln addition, it is preferred that this material be free of color bodies which become noticeable when the aminoplast (C) is applied to a fabric, or during the lifetime of the treated fabric.

The compound 2,7-dioxo-4,5-dimethyldecahydropyrimido-[4,S-dI-pyrimidine suitable for use in the present invention is conveniently and preferably prepared according to the following procedure, it being understood, of course, that other methods of synthesis can be used without departing from the spirit of the inventon. Thus, 5,285 parts by weight (120 moles) of acetaldehyde are charged to a suitable conventional reaction vessel and cooled to below C. Then a solution of 3,600 parts by weight (60 moles) of urea and 645 parts by weight of reagent grade sulfuric acid (98 percent) in 4,275 parts by weight of water are added dropwise with stirring to the acetaldeyde. During the addition, a suitable cooling means (e.g., an ice-bath) is applied to the reaction vessel, and the rate of addition is adjusted, if necessary, in order to maintain the reaction system at a temperature of about 20C. When the addition is complete, the reaction mixture is heated to atmospheric reflux temperature and maintained thereat for 1 hour. Thereafter, the reaction mixture is cooled to ambient temperature, diluted with water, and filtered to isolate the crystalline product, (A). The product is washed with water, then with methanol, and finally recrystallized from water. After drying the recrystallized product at 70C., it weighs 1,467 parts percent of the theroretical yield based on urea) and melts at 275280C. Elemental analysis of the product corresponds to the formula C,H,,N,O,.

The material 2,7-dioxo-4,S-dimethyl-decahydropyrimido-[4,5-dlpyrimidine, (A), is reacted with glyoxal, according to the present invention, as follows:

decahydropyrimido-[4,5-d]-pyrimidine adduct, (B), is then further reacted, according to the present invention, by contacting and reacting the adduct with between about l.0 and about 3.0 molar proportions of formaldehyde as illustrated in the following equation:

EQUATION II .wnuc'r (B) nHCHO I -(CHzOH) n (CHI-HEP HO OH (C) The exact nature of adduct (B) in Reaction I, above, is not known but is believed to be a mixture as shown in the equation; likewise, methylolation of the intermediate (B) of Equation I yield what is believed to be the 2,7-dioxo-4,5-dimethyl-decahydropyrimido-[4,5-d pyrimidine/Glyoxal/HCHO mixture (C) illustrated in Equation ll.

Intermediate (B) is best prepared by reacting equimolar upon of glyoxal and (A) in a hydroxylic medium, preferably water, at elevated temperatures, e.g., in the range of about 40C. to about C, and then the reaction is completed by increasing the temperature to atmospheric reflux for a relatively short period of time. Usually, it is best to maintain the lower temperature for less than about an hour and then bring the reaction mixture to reflux for about 3 to about 15 minutes. Of course, these temperatures may be varied considerably, depending upo concentrations of reactants, medium used, and other like factors. It should be understood that, in view of the fact that the reaction proceeds rather readily, a wide variety of temperatures, concentrations and pressures is permissible, the reaction conditions just mentioned being those best suited for equimolar proportions of reactants. Obviously, pressures above or below atmospheric require higher or lower temperatures, respectively; obviously, also, lean or excess concentrations, below or above stoichiometric, affect the temperature requirements for optimum results. In short, the reaction conditions are quite flexible, the stringencies being imposed by desired efiiciencies.

Conversion of intermediate (B) to the composition (C) of Equation ll, above, likewise admits of a wide variety of reaction conditions. Reaction is best carried out in a hydroxylic medium, usually water. Generally. between about 1.0 and about 3.0 molar proportions of formaldehyde, preferably between about 1.90 and about 2.10, is used based on adduct (8). Typical desirable formaldehyde sources are formalin, paraforrnaldehyde, and the like.

Admixture of adduct (B) with, say, an aqueous solution of formaldehyde gives rise to an exotherm. When the exotherm subsides (about 40), the mixture of reactants is preferably heated for up to several hours, cooled and pH adjusted to about neutral. Broadly, a temperature above about 40C to about C is contemplated herein, the upper temperature being, preferably, no greater than about atmospheric reflux temperature.

As in the case of the Equation I reaction described hereinbefore, reaction conditions for the Equation II reaction are very flexible, the stringencies also generally being dictated by desired efficiencies. If pressures above or below atmospheric are used, proportionately higher or lower temperatures, respectively, are usually indicated; likewise, lean or excess concentrations of formaldehyde with respect to adduct (B) could affect the temperature requirements for optimum results, as would of course, the amount of water or other hydroxylic medium used relative to the reactants.

Fabric treatment is carried out in a conventional pad bath in an aqueous medium containing the resinforming material (C) and a acidic curing catalyst as the principal ingredients. Generally, small amounts of surfactant and softener are present to enhance transfer of aminoplast material (C) to the fabric being treated.

The catalyst functions to catalyze the curing process which takes between about 5 seconds and about 30 minutes, preferably between about 3 minutes and about 15 minutes, at temperatures in the range of about 275F to about 425F, preferably between about 300F and about 350F. Substances suitable for catalysing the curing process include any conventional acidic catalysts or like catalysts heretofore known to be useful in catalysing the curing of conventional aminoplast materials. Such acid catalysts are employed in conventional amounts, e.g., at a concentration of between about 1 percent and about 50 percent by weight, based on the weight of aminoplast material. Typical catalysts contemplated herein are the water-soluble inorganic salts which behave as so-called latent acid catalysts, e.g., ammonium chloride, magnesium chloride, zinc nitrate, and the like.

According to a preferred mode of carrying out the fabric treatment process of the present invention, the aqueous reaction mixture containing the novel composition of matter (C) dissolved therein is cooled to ambient temperature, brought to a pH of about 7.0, and filtered to remove any insolubles which may be present. Then it is diluted with water to the desired concentration, mixed with a conventional amount of an acidic curing catalyst, and the fabric to be treated is immersed therein. The amount of resin pickup experienced by the substrate fabric is determined in large measure by the concentration of the resin-forming material, (C), in

the aqueous pad bath solution. Generally, the concentration of (C) in the pad bath solution (which can be determined gravimetrically) ranges between about 2 percent or less and about 65 percent by weight or more, for cellulosic fabrics. Preferably, a pad bath concentration of between about 5 percent and about 45 percent is used, with a concentration of between 10 percent and about percent being especially preferred. Percentages are based upon the total weight of the pad bath solution. The particular desired conccntration of resin-forming substance in any given instance can be conveniently achieved by appropriate adjustment of the concentrations of reactants i.e., (A)/glyoxal/HCHO) or by the judicious addition of water to an initially relatively highly concentrated solution of resinforming compound (C).

After saturating the fabric with the pad bath solution, the treated fabric is withdrawn from the bath, wrung between rollers made of an inert material (e.g., metal,

ceramic, rubber, and the like), preferably rubber rollers or adjacent, cooperatively-functioning stainless steel/rubber rollers, dried and simultaneously or subsequently heat cured at a temperature within the aforementioned range. The heat curing step can, if desired be conducted by contacting the fabric with heated metal rollers, preferably heated stainless steel rollers.

In the present invention, the percent pickup of the (A)/Glyoxal/l-ICHO composition is measured as: percent Wet Pickup, after immersion in the pad bath solution; percent Dry Pickup, after curing; percent Dry Pickup, after I wash; and percent Dry Pickup, after 2i washes.

As will be seen hereinafter, all tests are comparative tests using commercial resins as controls and comparing these resins with the novel composition (C) of the instant discovery. The tests recorded herein, other than resin pickup" characteristics, are intended to illustrate the effectiveness of compound (C) with respect to wrinkle recovery, hand, deterioration of fabric, soil redeposition, and the like. Obviously, permanent press resins are not attractive if they deleteriously affect fiber strength, if wrinkle recovery is poor, etc.

Fabrics, particularly cellulosic fabrics, treated with aminoplast material (C) according to the present invention exhibit as will be seen hereinafter, very desirable and valuable permanent press properties. The examples which follow teach the novel adducts (B) and (C) of the instant discovery and processes for preparing said. In addition, treatment of fabrics with resinforming compound (C) is fully disclosed, as well as a number of tests comparing the latter's efficacy with that of the following commerically popular resinforming compounds:

AEROTEX" 82 (carbamata) PERMAFRESH' 113B (dimethyloldlhydroxyethylaneuraa) DMDHEU Trademark for permanent press compound sold by Sun Chemical Co, Wood River Junction, R.l.

"Trademark for permanent press compound sold by American Cyan amid Co., Bound Brook, NJ.

DESCRIPTION OF PREFERRED EMBODIMENTS The following examples are merely intended to be illustrative of certain of the preferred embodiments within the spirit and scope of the present invention and, therefore, are not to be interpreted too restrictively; parts and percentages given in the examples are by weight, unless otherwise indicated:

EXAMPLE I reflux (103C) and held at that temperature for minutes before cooling the reaction mixture to ambient temperature and then filtering to remove unreacted 2,- 7-dioxo-4,5-dimethyl-decahydropyrimido-[4,5-d1- pyrimidine (147 grams). The filtrate (1055 grams) therefore contains 395 grams (approximately 2 moles) of reacted (A), i.e., the adduct (B), described hereinabove in Equation I, in solution.

EXAMPLE 2 To the filtrate, 1,055 grams, of Example 1 containing intermediate adduct (B) is charged 487 grams of 37 percent aqueous uninhibited formaldehyde solution, the same reaction vessel being used. When the resulting exotherm subsides at about 40C, the reaction mixture is heated to atmospheric reflux and held at reflux for three hours, at which time the mixture is cooled to ambient temperature and its pH adjusted to 7 using triethanolamine. The resulting product (A)/Glyoxal/HCHO compound (C) mixture of Equation II analyzes and compares with the aforementioned commerical aminoplast materials as follows:

TABLE I %free Compound Solids pH HCHO Aerotex 82 48:2 6.5 3.2 Permafresb 113B 45fl" 5.9 0 (A )lGlyoxal/HCHO 39 7.0 1.5

"Published values EXAMPLE 3 The product (A)/Glyoxal/HCHO composition (C) of Example 2, above, is used to treat plain weave white 50/50 cotton-polyester (PE) cloth, of the type used in shirts or household goods (e.g., sheets and pillowcases). The test procedure is as follows:

Bath:

compound tested (dry weight basis Surfactant (Triton* X l 00 Softener (Lubritron" KN) Catalyst-KR(MgCL,solution)"" Water Procedure:

Standard Pad Bath 70-80% Wet Pickup Dry at 220F for 12 minutes Cure at 325F for 12 minutes 7-9% Dry Pickup After wash Half of the test swatches are laundered through cycyles Tests:

Wrinkle Recovery Stiffness Tearing Strength Abrasion Resistance (ASTM D-l l75-64T) Triton X-l00 is a trademark for an alkylaryl polyether alcohol surfactant sold by Rohm 8L Haas Co., Philadelphia, Pa. "Lubriton KN is a trademark for a sofiener comprised of a non-ionic arqulsion ofa high density olefin sold by Chas. S. Tanner Co., Warwick, ""Catalyst-KR is a magnesium chloride-based catalyst solution sold by Sun Chemical Co., Wood River Junction. R.I.

The following table shows the pickup properties of each of the controls as compared with compound (C), the product of Example 2, above:

TABLE II RESIN ADD-ON Wet 1; Dry Dry Dry Pickup Pickup Pickup Pickup (after I (after 21 wash) washes) Aerotex 82 78 7.0 5.4 3.1 Permfresh 113B 78 8.7 6.5 3.5 (A)/Glyoxal/HCHO 77.7 8.9 3.6 1.7

Wrinkle recovery characteristics of the fabric of Example 3, above, treated with the compounds of Table II is determined by a well-known method: ASTM D-l 2- -67-Warp direction only. The results of these tests follow:

TABLE III WRINKLE RECOVERY Recovery in Degrees After 20 Initial Wash Cycles Blank (Untreated 50/50 PEzCotton) I07 I20 Aerotex 82 142 142 CONTROLS Permafresh l3B I45 I44 (A)/GlyoxaI/HCHO I40 Cantilever stiffness of the fabric of Example 3 using the compounds of Table II is determined using the method: ASTM D-l388-64-Warp direction only. The results are as follows:

TABLE IV CANTILEVER STIFFNESS Flexural Rigidity (mg-cm) After 20 Initial Wash cycles Blank (Untreated 50/50 PEzCotton) 79.95 67.58 Aerotex 82 88.68 62.l7

CONTROLS Permafresh 1138 89.43 55.94 (A)/Glyoxal/HCHO 65.25 60.73

Tearing strength of the fabric of Example 3, above,

using the compounds of Table II is determined by the method: ASTM D-226l-64T-Warp direction only. The results are as follows:

TABLE V TEARING STRENGTH BY THE TONGUE (SINGLE RIP) METHOD Break Load (in pounds) After 20 Initial Wash Cycles Blank (Untreated 50/50 PEzCotton 3.14 4.08 Aerotex 3.62 3.69

CONTROLS Pennafresh 1138 3.75 4.13 (A)/Glyoxal/HCHO 3.02 2.97

Conventional soil redeposition tests showed the product of Example 2, Le, compound (C), to be superior to Permafresh l l3B (DMDHEU). Using a small amount of anti-soil-redposition agent for polyester/cotton blends when subjecting the fabric of Example 3, treated as taught in the same Example, to an otherwise conventional soil redeposition test showed the fabric treated with (A)/Gyloxal/HCHO compound (C) performed as well as the Aerotex 82 treated fabric and better than the Permafresh l13B-treated fabric under the same conditions. In other words, the Aerotex 82- treated fabric and the compound (C)-treated fabric both remained almost completely white. The anti-soilredeposition agent used is a water-soluble methyl cellulose derivative (4000 cps) bearing the trademark ME THOCEL-JO-HG and sold by Dow Chemical Corp., Midland, Michigan. A concentration of 1 percent, by weight, of Methocel-HG is added to the conventional soil redeposition test soiling bath alluded to hereinabove', the concentration, viz., 1 percent by weight, is based on the total weight of the soil bath. The use of methyl cellulose derivatives is described in US. Pat. No. 3,668,000 filed Mar. 2, 1970.

As is evident from Table III and IV, above, the wrinkle recovery and stiffness performance of compound (C) compares very favorably with the performance of the commercial resins, even after multiple launderings. This indicates, in the case of wrinkle recovery, good bonding of the compound (C) resin to the fabric. Tear strength data reported in Table V, above, showed compound (C), like the commercial controls, produced no significant deterioration in fiber strength. Abrasion resistance tests (ASTM D-] 175-64T) not tabulated hereinabove, likewise indicated no significant deterioration in fiber strength.

Pursuant to statutory requirements, there are described above the invention and what are now considered its best embodiments. It should be understood, however, that the invention can be practiced otherwise than as specifically described, within the scope of the appended claims.

What is claimed is:

l. A process for treating fabric to impart permanent press properties thereto which comprises contacting the fabric with an aqueous solution of the methylolated aminoplast material comprising a mixture of compounds of the formulae:

and

\ (CHZCH)n N =f car-"HM --N I CH3 N N HO OH wherein n is an integer from 1 to 2, inclusive, and an acidic curing catalyst and subjecting the thus treated 5 fabric to elevated temperatures sufficient to cure said aminiplast material to a resin consistency providing permanent press properties to the fabric.

2. The process of claim 1 wherein the fabric is a cel lulosic fabric.

3. The process of claim 2 wherein the fabric is a polyester/cotton blend.

4. the process of claim 3 wherein the acidic curing catalyst is selected from the group consisting of water soluble inorganic salts which behave as latent acid catalysts.

5. The process of claim 4 wherein the acidic curing catalyst is magnesium chloride.

6. The process of claim 5 wherein the curing temper- 3Q ature is in the range of about 275F to about 425F.

7. The process of claim 6 wherein the methylolated aminoplast material is present in the treating solution in a concentration between about. 2 percent and about 65 percent by weight. 

2. The process of claim 1 wherein the fabric is a cellulosic fabric.
 3. The process of claim 2 wherein the fabric is a polyester/cotton blend.
 4. the process of claim 3 wherein the acidic curing catalyst is selected from the group consisting of water soluble inorganic salts which behave as latent acid catalysts.
 5. The process of claim 4 wherein the acidic curing catalyst is magnesium chloride.
 6. The process of claim 5 wherein the curing temperature is in the range of about 275*F to about 425*F.
 7. The process of claim 6 wherein the methylolated aminoplast material is present in the treating solution in a concentration between about 2 percent and about 65 percent by weight. 